Management of Patients with Long QT Syndrome

Abstract

Long QT syndrome (LQTS) is a rare cardiac channelopathy associated with syncope and sudden death due to torsades de pointes and ventricular fibrillation. Syncope and sudden death are frequently associated with physical and emotional stress. Management of patients with LQTS consists of life-style modification, β-blockers, left cardiac sympathetic denervation (LCSD), and implantable cardioverter-defibrillator (ICD) implantation. Prohibition of competitive exercise and avoidance of QT-prolonging drugs are important issues in life-style modification. Although β-blockers are the primary treatment modality for patients with LQTS, these drugs are not completely effective in some patients. Lifelong ICD implantation in young and active patients is associated with significant complications. LCSD is a relatively simple and highly effective surgical procedure. However, LCSD is rarely used.

Polyunsaturated fatty acids produce a range of activators for heterogeneous IKs channel dysfunction

“…Entry into cardiac arrhythmia in patients with LQT1 is often triggered by β-adrenergic stimulation, whether by exercise or intense emotional stress (Bohnen et al, 2017;Schwartz, et al, 2012;Wu et al, 2016). Treatment options for LQTS include pharmacological attenuation of β-adrenergic stimulation by β blockers or the implantation of a cardioverter defibrillator (Schwartz et al, 2012;Cho, 2016;Waddell-Smith and Skinner, 2016). Though these treatments help to prevent arrhythmia or stop arrhythmia, they do not work for all individuals (Chockalingam et al, 2012;Schwartz et al, 2012), and they do not directly target the underlying channelopathies that lead to LQTS (Schwartz et al, 2017).…”

ω‐6 and ω‐9 polyunsaturated fatty acids with double bonds near the carboxyl head have the highest affinity and largest effects on the cardiac IKs potassium channel

“…Current treatment options for LQTS are the prescription of β‐blockers or the implantation of a cardiac defibrillator . However, effective at preventing arrhythmia from causing sudden cardiac death, these treatments do not target the root cause of LQTS (ie in LQT1, defects in the cardiac I Ks channel).…”

Assessing Candidacy for Primary Preventative Implantable Cardioverter-defibrillators in Pediatric Patients with Ion Channelopathies: Weighing the Risks and Benefits

“…14 Left cardiac sympathetic denervation (LCSD) has also been found to be effective and has been used in patients refractory to or unable to take ß-blockers. 15 The "pyramid" of risk stratification for LQTS takes into account the patient's known genetic mutations, sex, corrected QT interval (QTc), and history of cardiac events ( Figure 1) and can help to guide management as well as decision-making processes regarding primary ICD placement. 8 Those who are at the highest risk for SCD before the age of 40 years, without appropriate intervention, include those with LQT1-causative mutations on more than one KCNQ1 allele; those with ≥ 10 cardiac events before the age of 18 years; and/or those with Timothy syndrome.…”